I'm glad you find the popup useful. I remember some negative feedback when we introduced it.
A decision was made that a popup menu doesn't fit in the UI for creating elements in this way. Given that a user can still change this after creation by setting the tagged value I wouldn't think it was a serious problem. Where would a popup be displayed?
Even if we found somewhere that worked to display the menu in this one place, others would have the same problem.
Create multiple elements from quicklinker
Apply the stereotype to existing elements (toolbox or dialog)
Package List, Specification Manager, Diagram List
Pattern import?
API
Even if it was possible to make all of these (except API) behave identically, I don't think it would necessarily make a better user experience.
(My emphasis)
Then you don't use EA in an enterprise scale production environment.
I may be creating 4-5 elements in a minute. Holding the Add Element... dialog open means I can cut down the number of clicks and mouse movements to create elements. Not being able to set the sub menu means suddenly I have
many more clicks and mouse movements per item and I have to post-process the items re-making decisions.
Carpal tunnel syndrome is a possibility.
Further as a casual end-user (that is MY users - whose day job is NOT modeller), it isn't apparent to me where the decision I've made ends up (that is did it set a tagged value and if so which one)? We want to reduce "friction" for our end-users. We're everywhere competing against Visio, other tools.
I've observed elsewhere that for a product named "Enterprise Architect", operating it at enterprise scale for enterprise models is problematic.
Now as to how far to make things consistent.
Sparx has already decided to make things inconsistent, "Madam, we've determined what you are, now we're just arguing the price." I see no problem with gradually implementing the consistency over time. Sparx might even ask the users what order they might like the mechanisms implemented.

Paolo